Finfet with self-aligned source/drain

ABSTRACT

A semiconductor device includes a fin structure, first and second gate structures, a source/drain region, a source/drain contact layer and a separation layer. The fin structure protrudes from an isolation insulating layer disposed over a substrate and extends in a first direction. The first and second gate structures are formed over the fin structure and extend in a second direction crossing the first direction. The source/drain region is disposed between the first and second gate structures. The interlayer insulating layer is disposed over the fin structure, the first and second gate structures and the source/drain region. The first source/drain contact layer is disposed on the first source/drain region. The separation layer is disposed adjacent to the first source/drain contact layer. Ends of the first and second gate structures and an end of the source drain contact layer are in contact with a same face of the separation layer.

RELATED APPLICATIONS

This application is a division of U.S. patent application Ser. No.15/157,274 filed on May 17, 2016, which claims a priority of U.S.Provisional Application No. 62/261,268 filed Nov. 30, 2015, the entirecontents of which are incorporated herein by reference.

TECHNICAL FIELD

The disclosure relates to a method for manufacturing a semiconductordevice, and more particularly to a structure and a manufacturing methodfor a self-align contact structure over source/drain regions.

BACKGROUND

With a decrease of dimensions of semiconductor devices, a self-alignedcontact (SAC) has been widely utilized for fabricating, e.g.,source/drain (S/D) contacts arranged closer to gate structures in afield effect transistor (FET). Typically, a SAC is fabricated bypatterning an interlayer dielectric (ILD) layer, under which a contactetch-stop layer (CESL) is formed over the gate structure having sidewallspacers. The initial etching of the ILD layer stops at the CESL, andthen the CESL is etched to form the SAC. As the device density increases(i.e., the dimensions of semiconductor device decreases), the thicknessof the sidewall spacer becomes thinner, which may cause a short circuitbetween the S/D contact and the gate electrodes. Further, a separationbetween two adjacent source/drain contacts has become tight.Accordingly, it has been required to provide SAC structures andmanufacturing process with improved electrical isolation between the S/Dcontacts.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure is best understood from the following detaileddescription when read with the accompanying figures. It is emphasizedthat, in accordance with the standard practice in the industry, variousfeatures are not drawn to scale and are used for illustration purposesonly. In fact, the dimensions of the various features may be arbitrarilyincreased or reduced for clarity of discussion.

FIG. 1A-8D show various stages of an exemplary sequential fabricationprocess of a semiconductor device according to one embodiment of thepresent disclosure.

FIGS. 9 and 10 show exemplary layout structures of a semiconductordevice according to one embodiment of the present disclosure.

FIGS. 11A-15D show various stages of an exemplary sequential fabricationprocess of a semiconductor device according to one embodiment of thepresent disclosure.

FIGS. 16A-20D show various stages of an exemplary sequential fabricationprocess of a semiconductor device according to one embodiment of thepresent disclosure.

FIGS. 21A-21D show an exemplary structure of a semiconductor deviceaccording to one embodiment of the present disclosure.

DETAILED DESCRIPTION

It is to be understood that the following disclosure provides manydifferent embodiments, or examples, for implementing different featuresof the invention. Specific embodiments or examples of components andarrangements are described below to simplify the present disclosure.These are, of course, merely examples and are not intended to belimiting. For example, dimensions of elements are not limited to thedisclosed range or values, but may depend upon process conditions and/ordesired properties of the device. Moreover, the formation of a firstfeature over or on a second feature in the description that follows mayinclude embodiments in which the first and second features are formed indirect contact, and may also include embodiments in which additionalfeatures may be formed interposing the first and second features, suchthat the first and second features may not be in direct contact. Variousfeatures may be arbitrarily drawn in different scales for simplicity andclarity.

Further, spatially relative terms, such as “beneath,” “below,” “lower,”“above,” “upper” and the like, may be used herein for ease ofdescription to describe one element or feature's relationship to anotherelement(s) or feature(s) as illustrated in the figures. The spatiallyrelative terms are intended to encompass different orientations of thedevice in use or operation in addition to the orientation depicted inthe figures. The apparatus may be otherwise oriented (rotated 90 degreesor at other orientations) and the spatially relative descriptors usedherein may likewise be interpreted accordingly. In addition, the term“made of” may mean either “comprising” or “consisting of.”

FIG. 1A-8D show various stages of an exemplary sequential fabricationprocess of a semiconductor device according to one embodiment of thepresent disclosure. It is understood that additional operations can beprovided before, during, and after processes shown by FIGS. 1A-8D, andsome of the operations described below can be replaced or eliminated,for additional embodiments of the method. The order of theoperations/processes may be interchangeable.

FIGS. 1A-1C show one stage of a sequential fabrication process of asemiconductor device according to one embodiment of the presentdisclosure. FIG. 1A shows a plan (top) view, FIG. 1B shows a crosssectional view along line X1-X1 of FIG. 1A, and FIG. 1C shows a crosssectional view along line Y1-Y1 of FIG. 1A.

FIGS. 1A-1C show a structure of a semiconductor device after metal gatestructures are formed. In FIGS. 1A-IC, a metal gate structure 40 isformed over a channel layer, for example, a part of a fin structure 20,which is formed over a substrate 10. The metal gate structure 40 isdisposed over the fin structure 20 in the Z direction. The metal gatestructure 10 extends in the Y direction and is arranged in the Xdirection, while the fin structure 20 extends in the X direction and isarranged in the Y direction. The thickness of the metal gate structures40 is in a range from about 15 nm to about 50 nm in some embodiments.The metal gate structure 40 includes a gate dielectric layer (not shown)formed by one or more layers of dielectric materials and a metal gateelectrode (not shown) formed by one or more layers of conductivematerials. The metal gate structure 40 further includes a cap insulatinglayer disposed over the metal gate electrode in some embodiments. Thewidth of the metal gate structure 40 is in a range from about 5 nm toabout 15 nm in some embodiments.

As shown in FIG. 1B, sidewall spacers 42 (omitted in FIG. 1A) are formedon both sidewalls of the metal gate structure 40. The film thickness ofthe sidewall spacers 42 at the bottom of the sidewall spacers is in arange from about 1 nm to about 10 nm in some embodiments, and is in arange from about 2 nm to about 8 nm in other embodiments.

As shown in FIGS. 1B and 1C, an isolation insulating layer 30 is formedover the substrate 10. A bottom portion of the fin structure 20 isembedded in the isolation insulating layer 30 and an upper portion(channel layer) of the fin structure 20 protrudes from the isolationinsulating layer 30. The gate structure 40 is formed over the isolationinsulating layer 30.

In FIGS. 1A-1C, two metal gate structures 40 and four fin structures 20are illustrated. However, the number of the metal gate structures 40 andthe fin structures 20 is not limited to two and four, respectively.

FIG. 1D shows an exemplary structure of the metal gate structure 40. Themetal gate structure 40 includes a gate dielectric layer 13 and a metalgate electrode 17. The metal gate electrode 17 includes one or morelayers of metal material, such as Al, Cu, W, Ti, Ta, TiN, TiAl, TiAlC,TiAlN, TaN, NiSi, CoSi, other conductive materials. The gate dielectriclayer 13 is disposed between the channel layer of the fin structure 20and the metal gate electrode 17 and includes one or more layers of metaloxides such as a high-k metal oxide. Examples of metal oxides used forhigh-k dielectrics include oxides of Li, Be, Mg, Ca, Sr, Sc, Y, Zr, Hf,Al, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and/ormixtures thereof. In some embodiments, an interface dielectric layer 11made of, for example silicon dioxide, is formed between the channellayer and the gate dielectric layer.

In some embodiments, one or more work function adjustment layers 15 areinterposed between the gate dielectric layer 13 and the metal gateelectrode 17. The work function adjustment layers are made of aconductive material such as a single layer of TiN, TaN, TaAlC, TiC, TaC,Co, Al, TiAl, HfTi, TiSi, TaSi or TiAlC, or a multilayer of two or moreof these materials. For the n-channel FET, one or more of TaN, TaAlC,TiN, TiC, Co, TiAl, HfTi, TiSi and TaSi is used as the work functionadjustment layer, and for the p-channel FET, one or more of TiAlC, Al,TiAl, TaN, TaAlC, TiN, TiC and Co is used as the work functionadjustment layer.

The cap insulating layer 19 disposed over the metal gate electrode 17includes one or more layers of insulating material such as siliconnitride based material including SiN, SiCN and SiOCN.

The material of the sidewall spacer 42 includes one or more of SiO₂,SiN, SiOC or SiOCN. Further, as shown in FIGS. 1B and 1C, a firstinterlayer dielectric layer (ILD) 50 is formed over the isolationinsulating layer 30 and the gate structures 40 are embedded in the ILD50. In FIG. 1A, the substrate 10, the isolation insulating layer 30 andfirst ILD 50 are omitted.

The structure of FIGS. 1A-IC may be fabricated by the followingoperations. In this embodiment, fin field effect transistors (Fin FETs)fabricated by a gate-replacement process are employed.

First, a fin structure is fabricated over a substrate. The fin structureincludes a bottom region and an upper region as a channel region. Thesubstrate is, for example, a p-type silicon substrate with an impurityconcentration in a range from about 1×10¹⁵ cm⁻³ to about 1×10¹⁸ cm⁻³. Inother embodiments, the substrate is an n-type silicon substrate with animpurity concentration in a range from about 1×10¹⁵ cm⁻³ to about 1×10¹⁸cm⁻³. Alternatively, the substrate may comprise another elementarysemiconductor, such as germanium; a compound semiconductor includingGroup IV-IV compound semiconductors such as SiC and SiGe, Group III-Vcompound semiconductors such as GaAs, GaP, GaN, InP, InAs, InSb, GaAsP,AlGaN, AlInAs, AlGaAs, GaInAs, GaInP, and/or GaInAsP; or combinationsthereof. In one embodiment, the substrate is a silicon layer of an SOI(silicon-on-insulator) substrate.

After forming the fin structure, an isolation insulating layer is formedover the fin structure. The isolation insulating layer includes one ormore layers of insulating materials such as silicon oxide, siliconoxynitride or silicon nitride, formed by LPCVD (low pressure chemicalvapor deposition), plasma-CVD or flowable CVD. The isolation insulatinglayer may be formed by one or more layers of spin-on-glass (SOG), SiO,SiON, SiOCN and/or fluorine-doped silicate glass (FSG).

After forming the isolation insulating layer over the fin structure, aplanarization operation is performed so as to remove part of theisolation insulating layer. The planarization operation may include achemical mechanical polishing (CMP) and/or an etch-back process. Then,the isolation insulating layer is further removed (recessed) so that theupper region of the fin structure is exposed.

A dummy gate structure is formed over the exposed fin structure. Thedummy gate structure includes a dummy gate electrode layer made of polysilicon and a dummy gate dielectric layer. Sidewall spacers includingone or more layers of insulating materials are also formed on sidewallsof the dummy gate electrode layer. After the dummy gate structure isformed, the fin structure not covered by the dummy gate structure isrecessed below the upper surface of the isolation insulating layer.Then, a source/drain region is formed over the recessed fin structure byusing an epitaxial growth method. The source/drain region may include astrain material to apply stress to the channel region.

Then, an interlayer dielectric layer (ILD) is formed over the dummy gatestructure and the source/drain region. After a planarization operation,the dummy gate structure is removed so as to make a gate space. Then, inthe gate space, a metal gate structure including a metal gate electrodeand a gate dielectric layer, such as a high-k dielectric layer, isformed.

FIGS. 2A-2C show one stage of a sequential fabrication process of asemiconductor device according to one embodiment of the presentdisclosure. FIG. 2A shows a plan (top) view, FIG. 2B shows a crosssectional view along line X1-X1 of FIG. 2A, and FIG. 2C shows a crosssectional view along line Y1-Y1 of FIG. 2A. In FIG. 2A, the substrate10, the isolation insulating layer 30 and first ILD 50 are omitted.

By the operation shown in FIGS. 2A-2C, the metal gate structures 40 arecut into plural pieces of gate structures for respective transistors. Amask pattern having an opening extending in the X direction, forexample, a photo resist pattern or a hard mask pattern, is formed overthe structure shown in FIGS. 1A-IC, and then patterning operations, suchas dry etching and/or wet etching, are performed so as to cut the metalgate patterns. Further, the first ILD 50 and the isolation insulatinglayer 30 are also etched, so that an opening 45 is formed. The isolationinsulating layer 30 is etched (recessed) to a depth D1, which is in arange from about 30 nm to about 60 nm in some embodiments. The width WIof the opening 45 is in a range from about 20 nm to about 80 nm in someembodiments. In some embodiments, the isolation insulating layer 30 isnot etched (i.e., D1=0).

FIGS. 3A-3C show one stage of a sequential fabrication process of asemiconductor device according to one embodiment of the presentdisclosure. FIG. 3A shows a plan (top) view, FIG. 3B shows a crosssectional view along line X1-X1 of FIG. 3A, and FIG. 3C shows a crosssectional view along line Y1-Y1 of FIG. 3A. In FIG. 3A, the substrate10, the isolation insulating layer 30 and first ILD 50 are omitted.

The opening 45 is filled with an insulating material, as shown in FIGS.3A-3C to form a separator 60. The insulating material for the separator60 includes one or more layers of insulating material having a higheretching selectivity against the materials of the isolation insulatinglayer 30 and the first ILD 50. Such materials include silicon nitridebased materials, such as SiN, SiON or SiOCN, or aluminum basedmaterials, such as aluminum oxide (which may collectively be referred toas AlO), aluminum oxynitride (which may collectively referred to asAlON) or aluminum nitride (which may collectively referred to as AlN).In one embodiment, SiN is used for the separator 60.

To form the separator 60, a blanket layer of an insulating material, forexample, SiN, is formed over the structure of FIGS. 2A-2C, and then aplanarization operation, such as an etch-back process and/or a chemicalmechanical polishing (CMP) process, is performed. The thickness T1 ofthe separator 60 is in a range from about 30 nm to about 60 nm in someembodiments.

FIGS. 4A-4D show one stage of a sequential fabrication process of asemiconductor device according to one embodiment of the presentdisclosure. FIG. 4A shows a plan (top) view, FIG. 4B shows a crosssectional view along line X1-X1 of FIG. 4A, FIG. 4C shows a crosssectional view along line Y1-Y1 of FIG. 4A, and FIG. 4D shows a crosssectional view along line X2-X2 of FIG. 4A. In FIG. 4A, the substrate10, the isolation insulating layer 30 and first ILD 50 are omitted.

A mask pattern 70 having an opening 75 extending in the Y direction, forexample, a photo resist pattern or a hard mask pattern, is formed overthe structure shown in FIGS. 3A-3C. The opening 75 corresponds tosources/drains of respective transistors. The edges of the opening 75along the Y direction may or may not overlap with the gate structures40.

In the present embodiment, a first transistor TR1, a second transistorTR2, a third transistor TR3, and a fourth transistor TR4 are formed. Thefirst transistor TR1 and the second transistor TR2 share the samesource/drain region 25A and the third transistor TR3 and the fourthtransistor TR4 share the same source/drain region 25B. In the presentembodiment, the source/drain regions 25A and 25B are formed over two finstructures, respectively. It is noted that in this disclosure, a sourceand a drain are used to merely distinguish one from another, and areinterchangeably used. A source/drain refers to one of a source or adrain.

FIGS. 5A-5D show one stage of a sequential fabrication process of asemiconductor device according to one embodiment of the presentdisclosure. FIG. 5A shows a plan (top) view, FIG. 5B shows a crosssectional view along line X1-X1 of FIG. 5A, FIG. 5C shows a crosssectional view along line Y1-Y1 of FIG. 5A, and FIG. 5D shows a crosssectional view along line X2-X2 of FIG. 5A. In FIG. 5A, the substrate10, the isolation insulating layer 30 and first ILD 50 are omitted.

By using the mask pattern 70 as an etching mask, the first ILD 50 ispartially etched to expose the source/drain regions 25A, 25B, as shownin FIGS. 5A and 5C. Since the separator 60 is made of a silicon nitridebased material (e.g., SiN) and the first ILD 50 is made of a siliconoxide based material (e.g., SiO₂), the openings 26A, 26B over thesource/drain regions 25A, 25B can be formed in a self-aligned manner inthe Y direction. Further, when the sidewall spacers 40 and the capinsulating layer 19 of the gate structure 40 are made of a siliconnitride based material (e.g., SiN), the openings 26A, 26B over thesource/drain regions 25A, 25B can also be formed in a self-alignedmanner in the X direction.

FIGS. 6A-6D show one stage of a sequential fabrication process of asemiconductor device according to one embodiment of the presentdisclosure. FIG. 6A shows a plan (top) view, FIG. 6B shows a crosssectional view along line X1-X1 of FIG. 6A, FIG. 6C shows a crosssectional view along line Y1-Y1 of FIG. 6A, and FIG. 6D shows a crosssectional view along line X2-X2 of FIG. 6A. In FIG. 6A, the substrate10, the isolation insulating layer 30 and first ILD 50 are omitted.

After the source/drain openings 26A and 26B are formed, a conductivematerial is formed in the openings to obtain a source/drain contactlayer 80. The conductive material for the source/drain contact layer 80includes one or more layers of W, Cu, Co, Ni, or silicide thereof. Toform the source/drain contact layer 80, a blanket layer of theconductive material is formed by, for example, CVD, physical vapordeposition (PVD) including sputtering, atomic layer deposition (ALD), orother suitable film forming methods. Then, a planarization operation,such as an etch-back process and/or a chemical mechanical polishing(CMP) process, is performed, thereby obtaining the structure of FIGS.6A-6D.

FIGS. 7A-7D show one stage of a sequential fabrication process of asemiconductor device according to one embodiment of the presentdisclosure. FIG. 7A shows a plan (top) view, FIG. 7B shows a crosssectional view along line X1-X1 of FIG. 7A, FIG. 7C shows a crosssectional view along line Y1-Y1 of FIG. 7A, and FIG. 7D shows a crosssectional view along line X2-X2 of FIG. 7A. In FIG. 7A, the substrate10, the isolation insulating layer 30, first ILD 50 and the second ILD85 are omitted.

After the source/drain contact layers 80 are formed, a second ILD 85 anda first via plug 90 are formed as shown in FIGS. 7A-7D. The second ILD85 includes one or more layers of insulating materials, such as SiO₂,SiOC SiOCN, or a low-k dielectric material (k=4-5). The first via plug90 can be formed by using a damascene process. The material for thefirst via plug 90 includes one or more layers of W, Co, Ni, Ti, TiN, Ta,TaN or other suitable conductive materials. In this embodiment, thefirst via plug 90 connects two source/drain contact layers 80 for thesource/drain regions 25A and 25B.

FIGS. 8A-8D show one stage of a sequential fabrication process of asemiconductor device according to one embodiment of the presentdisclosure. FIG. 8A shows a plan (top) view, FIG. 8B shows a crosssectional view along line X1-X1 of FIG. 8A, FIG. 8C shows a crosssectional view along line Y1-Y1 of FIG. 8A, and FIG. 8D shows a crosssectional view along line X2-X2 of FIG. 8A. In FIG. 8A, the substrate10, the isolation insulating layer 30, first ILD 50, the second ILD 85and the third ILD 95 are omitted.

A third ILD 95 and a first metal wiring 100 are subsequently formed overthe structure of FIGS. 7A-7D. The third ILD 95 includes one or morelayers of insulating materials, such as SiO₂, SiOC SiOCN, or a low-kdielectric material (k=4-5). The material for the first metal wiring 100includes one or more layers of Cu, Al, Ti, TiN, Ta, TaN or othersuitable conductive materials. The first metal wiring 100 can be formedby using a damascene process.

As shown in FIGS. 8A-8D, a first fin structure 20A and a second finstructure 20B isolated from the first fin structure 20A by an isolationinsulating layer 30 are disposed over a substrate 10. A first fin fieldeffect transistor (Fin FET) TR1 and a second Fin FET TR2 (see, FIG. 4A)are formed over the first fin structure 20A. The first Fin FET includesa first gate electrode 40A and the second Fin FET includes a second gateelectrode 40B. A first source/drain region 25A (see, FIG. 4A) is sharedby and disposed between the first Fin FET TR1 and the second Fin FETTR2. An interlayer insulating layer 50 is disposed over the first andsecond fin structures, the first and second Fin FETs and the firstsource/drain region. A first source/drain contact layer 80 is disposedon the first source/drain region and extends toward the second finstructure such that a part of the first source/drain contact layer 80 islocated over the isolation insulating layer 30. A first via plug 90 isdisposed on the part of the first source/drain contact layer 80 and islocated over the isolation insulating layer 30. A first metal wiringlayer 100 is disposed on the first via plug 90. An end of the firstsource/drain contact layer 80 is in contact with a separator 60 made ofan insulating material that is different from the isolation insulatinglayer 30 and the first ILD 50. Further, ends of the gate structures 40A,40B and an end of the first source drain contact layer 80 are in contactwith a same face of the separator 60.

It is understood that the device shown in FIGS. 8A-8D undergoes furtherCMOS processes to form various features such as interconnect metallayers, dielectric layers, passivation layers, etc.

FIG. 9 shows an exemplary layout structure of a semiconductor deviceaccording to one embodiment of the present disclosure.

In FIG. 9, a plurality of gate structures 41A-48A and 41B-48B extend inthe Y direction and are arranged in the X direction. In someembodiments, the plurality of gate structures 41A-48A and 41B-48B arearranged with a constant pitch in the X direction. The separator 60extends in the X direction and separates the gate structures 41A-48Afrom the gate structures 41B-48B. A source/drain region disposed betweenthe gate structure 43A and 44A is electrically connected by the firstvia plug 90 to a source/drain region disposed between the gate structure43B and 44B, and the first via plug 90 is connected to the first metalwiring 100. In FIG. 9, more than two gate structures and more than twosource/drain contact layers are in contact with the same face of theseparator 60

FIG. 10 shows an exemplary layout structure of standard cells for asemiconductor device according to one embodiment of the presentdisclosure.

In FIG. 10, a standard cell Cell B is disposed between standard cellsCell A and Cell C in the Y direction. Power supply lines Vdd and Vssextending in the X direction are disposed on the boundaries of thecells. The power supply lines Vdd and Vss are made by the first metalwirings 100.

The structure and manufacturing process explained by FIGS. 1A-8Dcorrespond to the formation of enclosed area A in FIG. 10. The structureand manufacturing process explained infra by FIGS. 11A-15D correspond tothe formation of enclosed area B in FIG. 10, the structure andmanufacturing process explained infra by FIGS. 16A-20D correspond to theformation of enclosed area C in FIG. 10, and The structure andmanufacturing process explained infra by FIGS. 21A-21D correspond to theformation of enclosed area D in FIG. 10.

In the area A, two source/drain contact layers adjacent to each other inthe Y direction are connected to the power supply line made by a metalwiring 100 via the first via plug 90. In the area A, a first finstructure 210 and a second fin structure 220 isolated from the first finstructure by an isolation insulating layer are disposed. A first finfield effect transistor (Fin FET) TR10 and a second Fin FET TR20 areboth formed over the first fin structure 210. The first Fin FET TR10includes a first gate electrode 410 and the second Fin FET TR20 includesa second gate electrode 420. A first source/drain region 310 is sharedby and disposed between the first Fin FET TR10 and the second Fin FETTR20. A first source/drain contact layer 810 is disposed on the firstsource/drain region 310 and extends toward the second fin structure 220such that a part of the first source/drain contact layer 810 is locatedover the isolation insulating layer. A contact plug 910 is disposed onthe part of the first source/drain contact layer and is located over theisolation insulating layer. A metal wiring layer 1010 (e.g., Vdd) isdisposed on the contact plug 910. An end of the first source/draincontact layer 810 is in contact with a separator 610.

Further, a third Fin FET TR30 and a fourth Fin FET TR40 are formed overthe second fin structure 220. The third Fin FET TR30 includes a thirdgate electrode 430, and the fourth Fin FET TR40 includes a fourth gateelectrode 440. A second source/drain region 320 is shared by anddisposed between the third Fin FET TR30 and the fourth Fin FET TR40. Asecond source/drain contact layer is disposed on the second source/drainregion 320 such that the first source/drain region and the secondsource/drain region are physically separated by the separator 60 and areelectrically connected by the first via plug 910.

Area B has a substantially similar structure to area A, except for thefollowing configurations. In area B, only one of the two source/draincontact layers adjacent to each other in the Y direction is connected tothe power supply line made by a metal wiring 100 via the first via plug90.

Area C has the substantially similar structure to area A, except for thefollowing configurations. In area C, neither of the two source/draincontact layers adjacent to each other in the Y direction is connected tothe power supply line.

Area D has a substantially similar structure to area A, except for thefollowing configuration. In area D, which is disposed within onestandard cell, two source/drain contact layers adjacent to each other inthe Y direction are connected to two metal wirings 100 via two first viaplugs 90, respectively.

FIGS. 11A-15D show various stages of an exemplary sequential fabricationprocess of the structure corresponding to area B of FIG. 10 according toone embodiment of the present disclosure. The material, configuration,structure and/or processes employed in FIGS. 1A-8D may be utilized inthe following embodiment and the details thereof may be omitted.

FIGS. 11A-11D show one stage of a sequential fabrication process of asemiconductor device according to one embodiment of the presentdisclosure. FIG. 11A shows a plan (top) view, FIG. 11B shows a crosssectional view along line X1-X1 of FIG. 11A, FIG. 11C shows a crosssectional view along line Y1-Y1 of FIG. 11A, and FIG. 11D shows a crosssectional view along line X2-X2 of FIG. 11A. In FIG. 11A, the substrate10, the isolation insulating layer 30, and first ILD 50 are omitted.

After the structure of FIGS. 3A-3C is formed, a mask pattern 70 havingan opening 75A, for example, a photo resist pattern or a hard maskpattern, is formed over the structure shown in FIGS. 3A-3C. The opening75A overlaps one of the source/drain regions (e.g., 25B, see, FIG. 4A)and a part of the separator 60, as shown in FIG. 11A.

FIGS. 12A-12D show one stage of a sequential fabrication process of asemiconductor device according to one embodiment of the presentdisclosure. FIG. 12A shows a plan (top) view, FIG. 12B shows a crosssectional view along line X1-X1 of FIG. 12A, FIG. 12C shows a crosssectional view along line Y1-Y1 of FIG. 12A, and FIG. 12D shows a crosssectional view along line X2-X2 of FIG. 12A. In FIG. 12A, the substrate10, the isolation insulating layer 30, and first ILD 50 are omitted.

By using the mask pattern 70 as an etching mask, the first ILD 50 ispartially etched to expose the source/drain region 25B, as shown inFIGS. 12A and 12C.

FIGS. 13A-13D show one stage of a sequential fabrication process of asemiconductor device according to one embodiment of the presentdisclosure. FIG. 13A shows a plan (top) view, FIG. 13B shows a crosssectional view along line X1-X1 of FIG. 13A, FIG. 13C shows a crosssectional view along line Y1-Y1 of FIG. 13A, and FIG. 13D shows a crosssectional view along line X2-X2 of FIG. 13A. In FIG. 13A, the substrate10, the isolation insulating layer 30, and first ILD 50 are omitted.

After the source/drain opening 26B is formed, a conductive material isformed in the opening 26B to obtain a source/drain contact layer 80A.

FIGS. 14A-14D show one stage of a sequential fabrication process of asemiconductor device according to one embodiment of the presentdisclosure. FIG. 14A shows a plan (top) view, FIG. 14B shows a crosssectional view along line X1-X1 of FIG. 14A, FIG. 14C shows a crosssectional view along line Y1-Y1 of FIG. 14A, and FIG. 14D shows a crosssectional view along line X2-X2 of FIG. 14A. In FIG. 14A, the substrate10, the isolation insulating layer 30, first ILD 50 and the second ILD85 are omitted.

After the source/drain contact layer 80A is formed, a second ILD 85 anda first via plug 90 are formed as shown in FIGS. 14A-14D. In thisembodiment, the first via plug 90 is connected to only a singlesource/drain contact layer 80A, unlike the embodiment shown in FIGS. 7Aand 7C, where the first via plug 90 is connected to two source/draincontact layers 80.

FIGS. 15A-15D show one stage of a sequential fabrication process of asemiconductor device according to one embodiment of the presentdisclosure. FIG. 15A shows a plan (top) view, FIG. 15B shows a crosssectional view along line X1-X1 of FIG. 15A, FIG. 15C shows a crosssectional view along line Y1-Y1 of FIG. 15A, and FIG. 15D shows a crosssectional view along line X2-X2 of FIG. 15A. In FIG. 15A, the substrate10, the isolation insulating layer 30, first ILD 50, the second ILD 85and the third ILD 95 are omitted.

In this embodiment, a third ILD 95 and a first metal wiring 100 aresubsequently formed over the structure of FIGS. 14A-14D, as shown inFIGS. 15A-15D.

In the embodiment of FIGS. 15A-15D, unlike the structures shown in FIGS.8A-8D, only one (e.g., 25B) of the two source/drain contact layer isconnected to the metal wiring 100 via the first via plug 90.

FIGS. 16A-20D show various stages of an exemplary sequential fabricationprocess of the structure corresponding to area C of FIG. 10 according toone embodiment of the present disclosure. The material, configuration,structure and/or processes employed in FIGS. 1A-8D may be utilized inthe following embodiment and the details thereof may be omitted.

FIGS. 16A-16D show one stage of a sequential fabrication process of asemiconductor device according to one embodiment of the presentdisclosure. FIG. 16A shows a plan (top) view, FIG. 16B shows a crosssectional view along line X1-X1 of FIG. 16A, FIG. 16C shows a crosssectional view along line Y1-Y1 of FIG. 16A, and FIG. 16D shows a crosssectional view along line X2-X2 of FIG. 16A. In FIG. 16A, the substrate10, the isolation insulating layer 30, and first ILD 50 are omitted.

After the structure of FIGS. 3A-3C is formed, a mask pattern 70 havingan opening 75B, for example, a photo resist pattern or a hard maskpattern, is formed over the structure shown in FIGS. 3A-3C. The opening75B overlaps one of the source/drain regions (e.g., 25B, see, FIG. 4A)but does not overlap the separator 60, as shown in FIG. 16A.

FIGS. 17A-17D show one stage of a sequential fabrication process of asemiconductor device according to one embodiment of the presentdisclosure. FIG. 17A shows a plan (top) view, FIG. 17B shows a crosssectional view along line X1-X1 of FIG. 17A, FIG. 17C shows a crosssectional view along line Y1-Y1 of FIG. 17A, and FIG. 17D shows a crosssectional view along line X2-X2 of FIG. 17A. In FIG. 17A, the substrate10, the isolation insulating layer 30, and first ILD 50 are omitted.

By using the mask pattern 70 as an etching mask, the first ILD 50 ispartially etched to form opening 26B exposing the source/drain region25B, as shown in FIGS. 17A and 17C.

FIGS. 18A-18D show one stage of a sequential fabrication process of asemiconductor device according to one embodiment of the presentdisclosure. FIG. 18A shows a plan (top) view, FIG. 18B shows a crosssectional view along line X1-X1 of FIG. 18A, FIG. 18C shows a crosssectional view along line Y1-Y1 of FIG. 18A, and FIG. 18D shows a crosssectional view along line X2-X2 of FIG. 18A. In FIG. 18A, the substrate10, the isolation insulating layer 30, and first ILD 50 are omitted.

After the source/drain opening 26B is formed, a conductive material isformed in the opening 26B to obtain a source/drain contact layer 80B.

FIGS. 19A-19D show one stage of a sequential fabrication process of asemiconductor device according to one embodiment of the presentdisclosure. FIG. 19A shows a plan (top) view, FIG. 19B shows a crosssectional view along line X1-X1 of FIG. 19A, FIG. 19C shows a crosssectional view along line Y1-Y1 of FIG. 19A, and FIG. 19D shows a crosssectional view along line X2-X2 of FIG. 19A. In FIG. 19A, the substrate10, the isolation insulating layer 30, first ILD 50 and the second ILD85 are omitted.

After the source/drain contact layer 80B is formed and a second ILD 85is formed as shown in FIGS. 19A-19D. In this embodiment, no first viaplug 90 is disposed on the source/drain contact layer 80B.

FIGS. 20A-20D show one stage of a sequential fabrication process of asemiconductor device according to one embodiment of the presentdisclosure. FIG. 20A shows a plan (top) view, FIG. 20B shows a crosssectional view along line X1-X1 of FIG. 20A, FIG. 20C shows a crosssectional view along line Y1-Y1 of FIG. 20A, and FIG. 20D shows a crosssectional view along line X2-X2 of FIG. 20A. In FIG. 20A, the substrate10, the isolation insulating layer 30, first ILD 50, the second ILD 85and the third ILD 95 are omitted.

A third ILD 95 and a first metal wiring 100 are subsequently formed overthe structure of FIGS. 19A-19D, as shown in FIGS. 20A-20D.

FIGS. 21A-21D show an exemplary structure of a semiconductor deviceaccording to one embodiment of the present disclosure. The structure andmanufacturing process explained below with FIGS. 21A-21D correspond toenclosed area D in FIG. 10.

As shown in FIGS. 21A-21D, a first fin structure 20A and a second finstructure 20B isolated from the first fin structure 20A by an isolationinsulating layer 30 are disposed over a substrate 10. A first fin fieldeffect transistor (Fin FET) TR1 and a second Fin FET TR2 (see, FIG. 4A)are formed over the first fin structure 20A, and a third Fin FET TR3 anda fourth Fin FET TR4 (see, FIG. 4A) are formed over the second finstructure 20B. The first Fin FET TR1 includes a first gate electrode40A, the second Fin FET TR2 includes a second gate electrode 40B, thethird Fin FET TR3 includes a third gate electrode 40C and the fourth FinFET TR4 includes a fourth gate electrode 40D. A first source/drainregion 25A (see, FIG. 4A) is shared by and disposed between the firstFin FET TR1 and the second Fin FET TR2, and a second source/drain region25B (see, FIG. 4A) is shared by and disposed between the third Fin FETTR3 and the fourth Fin FET TR4. An interlayer insulating layer 50 isdisposed over the first to fourth fin structures, the first to fourthFin FETs and the first and second source/drain regions. A firstsource/drain contact layer 80C is disposed on the first source/drainregion 25A and extends toward the second fin structure such that a partof the first source/drain contact layer 80C is located over theisolation insulating layer 30. A second source/drain contact layer 80Dis disposed on the second source/drain region 25B and extends toward thefirst fin structure such that a part of the second source/drain contactlayer 80C is located over the isolation insulating layer 30. A first viaplug 90C is disposed on the first source/drain contact layer 80C and asecond via plug 90D is disposed on the second source/drain contact layer80D. A first metal wiring layer 100C is disposed on the first via plug90C and a second metal wiring layer 100D is disposed on the second viaplug 90D. One end of the first source/drain contact layer 80C is incontact with a separator 60 and one end of the second source/draincontact layer 80D is in contact with the separator 60.

The various embodiments or examples described herein offer severaladvantages over the existing art. For example, in the presentdisclosure, since a source/drain contact layer 80 can be formed in aself-aligned manner by using the gate cutting process and the separator60, it is possible to reduce the circuit size, particularly, the size ofstandard cells. Further, it is possible to suppress the formation ofrounded shapes of the ends of the source/drain contact layers.

It will be understood that not all advantages have been necessarilydiscussed herein, no particular advantage is required for allembodiments or examples, and other embodiments or examples may offerdifferent advantages.

According to one aspect of the present disclosure, in a method ofmanufacturing a semiconductor device, a first fin structure and a secondfin structure are formed over a substrate. The first and second finstructures extend in a first direction and are arranged in a seconddirection crossing the first direction in parallel with each other. Anisolation insulating layer is formed over the substrate such that upperportions of the first and second fin structures are exposed from theisolation insulating layer. A first gate structure and a second gatestructure are formed over parts of the first and second fin structures.The first and second gate structures extend in the second direction andare arranged in the first direction in parallel with each other. Aninterlayer insulating layer is formed over the first and second gatestructures and the first and second fin structures. A first mask patternhaving first openings is formed over the interlayer insulating layer.The first openings are located above the first and second gatestructures, respectively. The first and second gate structures are cutthrough the first openings of the first mask pattern. The first maskpattern includes a second opening disposed between the first and secondgate structures in plan view. The isolation insulating layer and theinterlayer dielectric layer are etched through the second opening so asto form a first recess. An insulating layer is formed in the firstrecess. A second mask pattern having a third opening is formed so as toexpose a part of the insulating layer in the first recess and a part ofthe interlayer dielectric layer. The exposed part of the interlayerdielectric layer through the third opening are etched so as to form asecond recess. A conductive material is formed in the second recess.

According to another aspect of the present disclosure, a semiconductordevice includes a first fin structure and a second fin structure, afirst fin field effect transistor (Fin FET) and a second Fin FET, afirst source/drain region, an interlayer insulating layer, a firstsource/drain contact layer and a separation insulating layer. The secondfin structure is isolated from the first fin structure by an isolationinsulating layer. The first and second fin structures extend in a firstdirection. The first Fin FET and the second Fin FET are formed over thefirst fin structure. The first Fin FET includes a first gate electrode,and the second Fin FET includes a second gate electrode. The first andsecond gate electrodes extend in a second direction crossing the firstdirection. The first source/drain region is shared by and disposedbetween the first Fin FET and the second Fin FET. The interlayerinsulating layer is disposed over the first and second fin structures,the first and second Fin FETs and the first source/drain region. Thefirst source/drain contact layer is disposed on the first source/drainregion and extends toward the second fin structure such that a part ofthe first source/drain contact layer is located over the isolationinsulating layer. The separation insulating layer is disposed adjacentto the first source/drain contact layer. An end of the firstsource/drain contact layer is in contact with the separation insulatinglayer. The separation insulating layer is made of an insulating materialdifferent from the isolation insulating layer and the interlayerinsulating layer.

In accordance with yet another aspect of the present disclosure, asemiconductor device includes a first fin structure, a first gatestructure and a second gate structure, a first source/drain region, aninterlayer insulating layer, a first source/drain contact layer, and aseparation insulating layer. The first fin structure protrudes from anisolation insulating layer disposed over a substrate and extends in afirst direction. The first gate structure and the second gate structureare both formed over the first fin structure. The first and second gatestructures extend in a second direction crossing the first direction.The first source/drain region is disposed between the first gatestructure and the second gate structure. The interlayer insulating layeris disposed over the first fin structure, the first and second gatestructures and the first source/drain region. The first source/draincontact layer is disposed on the first source/drain region. Theseparation insulating layer is disposed adjacent to the firstsource/drain contact layer. An end of the first gate structure, an endof the second gate structure and an end of the first source draincontact layer are in contact with a same face of the separationinsulating layer.

The foregoing outlines features of several embodiments or examples sothat those skilled in the art may better understand the aspects of thepresent disclosure. Those skilled in the art should appreciate that theymay readily use the present disclosure as a basis for designing ormodifying other processes and structures for carrying out the samepurposes and/or achieving the same advantages of the embodiments orexamples introduced herein. Those skilled in the art should also realizethat such equivalent constructions do not depart from the spirit andscope of the present disclosure, and that they may make various changes,substitutions, and alterations herein without departing from the spiritand scope of the present disclosure.

What is claimed is:
 1. A semiconductor device, comprising: a first finstructure and a second fin structure isolated from the first finstructure by an isolation insulating layer, the first and second finstructures extending in a first direction; a first fin field effecttransistor (Fin FET) and a second Fin FET, both formed over the firstfin structure, the first Fin FET including a first gate electrode, thesecond Fin FET including a second gate electrode, the first and secondgate electrodes extending in a second direction crossing the firstdirection; a first source/drain region shared by and disposed betweenthe first Fin FET and the second Fin FET; an interlayer dielectric layerdisposed over the first and second fin structures, the first and secondFin FETs and the first source/drain region; a first source/drain contactlayer disposed on the first source/drain region and extending toward thesecond fin structure such that a part of the first source/drain contactlayer is located over the isolation insulating layer; and a separationinsulating layer disposed adjacent to the first source/drain contactlayer in the second direction, wherein: an end of the first source/draincontact layer is in contact with the separation insulating layer, andthe separation insulating layer is made of an insulating materialdifferent from the isolation insulating layer and the interlayerdielectric layer.
 2. The semiconductor device of claim 1, wherein thefirst source/drain contact layer includes at least one of W, Co, Ni, Ti,and Ta, a silicide thereof and a nitride thereof.
 3. The semiconductordevice of claim 1, wherein the insulating material of the separationinsulating layer is SiN.
 4. The semiconductor device of claim 1, furthercomprising a conductive plug on the separation insulating layer and thefirst source/drain contact layer.
 5. The semiconductor device of claim1, further comprising: a third Fin FET and a fourth Fin FET, both formedover the second fin structure, the third Fin FET including a third gateelectrode, the fourth Fin FET including a fourth gate electrode; asecond source/drain region shared by and disposed between the third FinFET and the fourth Fin FET; and a second source/drain contact layerdisposed on the second source/drain region and extending toward thefirst fin structure such that a part of the second source/drain contactlayer is located over the isolation insulating layer, wherein: an end ofthe second source/drain contact layer is in contact with the separationinsulating layer, and the second source/drain contact layer isphysically separated from the first source/drain contact layer by theseparation insulating layer.
 6. The semiconductor device of claim 5,wherein: the first gate electrode and the third gate electrode arealigned with each other, and the second gate electrode and the fourthgate electrode are aligned with each other.
 7. The semiconductor deviceof claim 5, further comprising a conductive plug on the separationinsulating layer, the first source/drain contact layer and the secondsource/drain contact layer.
 8. The semiconductor device of claim 1,further comprising: a third fin structure; a fifth Fin FET and a sixthFin FET, both formed over the third fin structure, the fifth Fin FETincluding a fifth gate electrode, the sixth Fin FET including a sixthgate electrode; a third source/drain region shared by and disposedbetween the fifth Fin FET and the sixth Fin FET; and a thirdsource/drain contact layer disposed on the third source/drain region,wherein the third source/drain contact layer is not electricallyconnected to an adjacent source/drain region in the second direction. 9.A semiconductor device, comprising: a first fin structure protrudingfrom an isolation insulating layer disposed over a substrate andextending in a first direction; a first gate structure and a second gatestructure, both formed over the first fin structure, the first andsecond gate structures extending in a second direction crossing thefirst direction; a first source/drain region disposed between the firstgate structure and the second gate structure; an interlayer dielectriclayer disposed over the first fin structure, the first and second gatestructures and the first source/drain region; a first source/draincontact layer disposed on the first source/drain region; and aseparation insulating layer disposed adjacent to the first source/draincontact layer, wherein an end of the first gate structure, an end of thesecond gate structure and an end of the first source drain contact layerare in contact with a same face of the separation insulating layer. 10.The semiconductor device of claim 9, wherein the separation insulatinglayer is made of an insulating material different from the isolationinsulating layer and the interlayer dielectric layer.
 11. Thesemiconductor device of claim 9, wherein the first source/drain contactlayer includes at least one of W, Co, Ni, Ti, and Ta, a silicide thereofand a nitride thereof.
 12. The semiconductor device of claim 9, whereinthe insulating material of the separation insulating layer is SiN. 13.The semiconductor device of claim 9, wherein more than two gatestructures and more than two source/drain contact layers are in contactwith the same face of the separation insulating layer.
 14. Thesemiconductor device of claim 9, further comprising a conductive plug onthe separation insulating layer and the first source/drain contactlayer.
 15. The semiconductor device of claim 9, further comprising: asecond fin structure protruding from the isolation insulating layer andextending in the first direction; a third gate structure and a fourthgate structure, both formed over the second fin structure, a secondsource/drain region disposed between the third gate structure and thefourth gate structure; and a second source/drain contact layer disposedon the second source/drain region and extending toward the second finstructure such that a part of the second source/drain contact layer islocated over the isolation insulating layer, wherein: an end of thesecond source/drain contact layer is in contact with the separationinsulating layer, and the second source/drain contact layer isphysically separated from the first source/drain contact layer by theseparation insulating layer.
 16. The semiconductor device of claim 15,wherein: the first gate structure and the third gate structure arealigned with each other, and the second gate structure and the fourthgate structure are aligned with each other.
 17. The semiconductor deviceof claim 15, further comprising a conductive plug on the separationinsulating layer, the first source/drain contact layer and the secondsource/drain contact layer.
 18. A semiconductor device, comprising: apair of first fin structures and a pair of second fin structures; afirst gate structure and a second gate structure, both formed over thepair of first fin structures, a first source/drain region disposedbetween the first gate structure and the second gate structure; a firstsource/drain contact layer disposed on the first source/drain region; athird gate structure and a fourth gate structure, both formed over thepair of second fin structures; a second source/drain region disposedbetween the third gate structure and the fourth gate structure; a secondsource/drain contact layer disposed on the second source/drain region aseparation insulating layer separating the first source/drain contactlayer from the second source/drain contact layer, wherein an end of thefirst gate structure, an end of the second gate structure and an end ofthe first source drain contact layer are in contact with one face of theseparation insulating layer, and an end of the third gate structure, anend of the fourth gate structure and an end of the second source draincontact layer are in contact with another face of the separationinsulating layer opposite to the one face.
 19. The semiconductor deviceof claim 18, further comprising an interlayer dielectric layer disposedover the first and second pair of fin structures, wherein the separationinsulating layer is made of an insulating material different from theinterlayer dielectric layer.
 20. The semiconductor device of claim 18,wherein the insulating material of the separation insulating layer isSiN.